Drill



Patented Oct. 3 1950 UNITED STATES PATENT OFFICE DRILL Carl C. Koeln,St. Louis, Mo. Application October 24, 1945, Serial No. 624,305

- 8 Claims. l

This invention pertains to drilling devices generally, and concernsitself more particularly with a double action earth drill for use withchurn drilling apparatus.

The use of churn drills in earth boring operations, such as the sinkingof deep wells, is well known in the art. The equipment used consists ofa cutting tool, or drill, attached to a rope or steel cable, by means ofwhich it is alternately hoisted and-abruptly droopped through a givendistance. Powered machines are usually employed to manipulate the drill,which, for oil drilling operation, weighs in the order of a ton or more.

The drill, per sewith which the instant invention deals, is an elongatedmetal shaft, commonly termed a shank, which ends in a sharp bitproviding the cutting portion of the tool. The repeatedY percussivestrokes of the bit against the substance being drilled (primarily rock)effect the cutting action, and, after each few feet of drilling, thecuttings are removed from the bore. For easy replacement of a Worn bit,this part of the drill is detachable from the shank.

It is a general aim of the invention to provide an improved drill of thetype described having for its end result greatly increased drillingefliciencies.

More specifically, it is an object of the invention to providefa drillcapable of producing a percussive vstroke in addition to, andapproximately equaling, its gravity stroke forthe same amount of poweras was formerly expended. in producing the gravity stroke alone.

Defining the general objects in specific terms, it is a purpose of theinvention to provide a drill having a spring driven hammer releasableafter the delivery of the drills kinitial gravity Vblow for imparting asecond cutting force to the drill bit and simultaneously effecting itsrotation.

Another purpose of the invention is to provide a device capable ofcarrying out the foregoing objects which is adaptable to presentlyemploy drills of the type described.

Still another object of the invention is to Vprovide a rock drill-capable of delivering an initial blow for setting its bit followed by asecond blow for rotating the bit to produce a chipping action.

A still further object of the invention is to provide a drill adaptablefor yuse as a churn drill in which a force is stored during its liftingstroke for subsequent release after the drills gravity stroke. Y

Othenobiects andadvantages willbecome ap- (Cl. Z-27.1)

parent as the description proceeds, and a more comprehensiveunderstanding of the invention will be afforded from the followingdetailed description when considered in conjunction with.

the accompanying drawing, in which:

Fig. 1 is an elevational View, in partial vertical section, of a drillembodying the instant invention showing the relative positions of itsparts upon completion of its upward stroke;

Fig. 2 is a view similar to that of Fig. 1 showing the relativepositions of the drills parts upon completion of its downward stroke;and

Figs. 3 to 7, inclusive, are cross-sectional views of the drillillustrated in Figs. 1 and 2, taken along the lines indicated.

In the form illustrated in the drawings, the invention is represented byan adaptation for use with presently .used drills comprising a shank IIand a drill bit, or cutting tool, I2, which latter element may bescrewed into the shank at I3. As contemplated in this form, a hammerassembly I4 embodying the instant invention is attached to the shank atI3 and the bit I2 is, in turn, attached to this assembly at I5. It willbe apparent to the reader, however, that the invention need not be soapplied, but may be made as a unit. In such case, the shank II and thebit I2 will conform exactly with those shown, the only probabledifference being that of the size of the shank II. This minor differencewill be explained later, at a, more appropriate place in thedescription.

With the understanding that the invention does not necessarilycontemplate an adapter for any drill, it will be described as comprisingthe shank I I and the bit I 2 between which is interposed the hammerassembly I 4.

The shank II may be thought of as an elongated metal shaft provided witha cable coupling I6 to which a cable is attached and by means of whichthe entire drill is raised and lowered by churn drilling apparatus toperform its drilling operation. The cable coupling I6 is -connected withthe shank II by means of a pin II and slot a vertically extending slot34 through which theV This slot is substantially com- Y pin 26 extends.plementary with the slots 24 and 25 in the walls of the bell 2|.

Retained within an internal bore 35 in the hammer member 21 is acompression spring 36 which seats, in one instance, against the bottomof the bore 35 and, in a second instance, against a bearing` plate 31movable against the pin 26. A section 38 of the hammer member 21 isthreaded to be screwed onto the latter member and is thus removabletherefrom. This expedient provides for the easy installation of thecompression spring 36 within the hammer.

parts, it is apparent that the bell 2| is vertically movable within thecasing I9, as is the bit mounting member 39. Similarly, the hammermember 21 is vertically movable within the bore 28 of the bell 2 I.Further, through the pin and slot arrangement for connecting the bitmounting member 39 with the casing I9, the former is rotatable withinthe latter in a plane normal to the axis of the entire drill assembly.The relative movement of these parts will now be described in connectionwith the drills operation.

Operation With the drill device assembled as illustrated in Fig. l, itis attached to the cable of the churn drilling apparatus by means of thecoupling I6. Under the lifting action of the drilling apparatus, theentire assembly is raised through a given distance from which point itis abruptly dropped to deliver the drill bit I2 with a gravity blow. Onthe upward stroke, the weight of the casing I9, together with that ofthe bit mounting member 39 and the drill bit I2, provides a gravity loadwhich is transmitted by means of the pin 26 against the spring seatmember 31. The lift- Slidable also within the casing I9 is a bit hmounting member 39 to which the drill bit I2 is attached at I5.' Thedrill mounting member 39 is attached to the casing I9 by means of aplurality of pins 4I and 42 projecting outwardly :c

lfrom the shank thereof into obliquely aligned slots 43 and 44 cut inthe walls of the casing, I9. These slots, Vthe purpose of which will bedescribed later, provide for the 'vertical movement of .the member 39within the casing I9, and,

when the drill is being lifted upwardly, the pins 4| and 42 attainpositions at the bottom of their respective slots 43 and 44.

The member 39 is also fashioned with a reduced section 45 'whichaccommodates extensions of a pair of trigger bell cranks 46 and 41retained within the walls of the casing I9 and arranged to providetriggers for locking the hammer mem- .lil

ber 21 in a position within the bell 2| to deliver a power stroke to thebit mounting member 39.

The triggers 46 'and 41 are pivoted, respectively, 'on pins 4B and 49about which they are movable to perform their desired function. Thetrigger 46 has an extension 5| projecting into the reduced section 45 ofthe member 39. Likewise, the trigger 41 has an extension `52 similarlyprojecting. Each of these extensions is shaped to form complementary camsurfaces with a cam surface l53 on the member 39. At their upper ends,both of the triggers 46 and 41 are shaped I' to form locking projections54 and 55 which are engagleable against a shoulder 56 on the member 38to lock the hammer member 21 in its cocked position.

To provide rotation for the bit mounting meinber 39 and, incidentally,the drill bit I2, the former member is fashioned at its upper surfaceWith a plurality of cam teeth 51 which, at a fixed relative position ofthe various parts of the drill to be more fully described, arecomplementary with a similar group of cam surfaces y58 fashioned on theundersurface of the movable section 38 of the hammer 21.

To provide a releasing force for the trigger mechanisms 46 and 41, thelower face of the bell 2| is fashioned with a cam surface 59 which isbrought into engagement with a cam surface 6| on the trigger 46 and acam surface 62 'on the trigger member 41.

ing forces acting through the shank I I are transmitted through thecrossbar 29 to the surface 32 of the hammer member 21, and the latter israised causing relative movement with the bell 22. As the hammer memberV21 is moved upwardly by the action of the crossbar 29, the pin 26 ismovable downwardly within the slots 24 and 25 of the bell 2|, therebycompressing the spring 36 as illustrated in Fig. l.

Simultaneous with the compressing action on the spring 36, the vweightof the bit 'mounting member 39 and the drill bit I2, acting through itscam surface/'53 against the extensions 5| and 52 of the triggers 46 and41, rotates these latter members inwardly to draw their lockingextensions 54 and l55 into engagement with the shoulder 56 on the hammermember 21 and thereby locks the same against movement under thecompressive forces of the spring 36. The foregoing action may bedescribed as that of cooking the drill, and is completely accomplishedon the lift stroke thereof.

When the drill is raised to a certain position by the drillingapparatus, it is abruptly dropped, and, through the weight of the entireassembly, the drill bit I2 is moved against the object to be drilledwith a gravity blow. As the drill bit I2 impinges against such anobject, a lower extension 65 of the casing I9 is moved into con'- tactwith a shoulder 66 on the drill bit I2, and the pins 4| and 42 arecammedwithin their respective slots 43 and 44 to rotate the bit mo'untingmember 39 in a manner such that its cam surfaces 51 will be positionedto receive the cam surfaces 58 ofthe hammer 21. In this manner, and whenthe two are brought together, rotation of the drill bit I2 will beeffected in a plane normal to the longitudinal axis of the drill.

When the casing member I9 is stopped in its .s downward path, relativeImotion between it and the bell 2| is possible, and the bell 2|continues to slide downwardly with respect thereto. Under this action,the -cam 'surface 59 on the lower extension of the bell 2| is movedb'ythe entire weight of the assembly extending thereabove against the-camsurfaces 6| and 62 of the triggers 46and 41, respectively, which vactionmoves them about 'their pivot points outwardly to withdraw the lockingextensions 54 and 55 from the shoulder 56, thereby releasing Athehammer-mem- 5. ber V2l for movement-under the expansive forces of thespring 36.- -This latter action delivers to the bit mounting member 39 ahammer blow which is transmitted therethrough to the bit I2. In'additionto the blow thus delivered, the drill bit l2 is rotated through a slightangle under the action of the cam surfaces 51 and 58 which gives to itan additional chippingv action. Y

It is to be pointed out, here, that through the free action of thehammer 21, with respect to the bell member 2l, no destructive force isapplied to the cable supporting the drill when the hammer delivers itspower stroke. The cable has become slack on lthe initial downward strokeof the drill assembly and, thereafter, the hammer 21 merely slides inthe bell member 2|, thus preventing the cable from receivingua suddenjerk which might otherwise break it.

It will be apparent that the weight of the bitmounting member 39 and thedrill bit l2, together with the casing I9, must be somewhat in excess ofthe compressive forces of the spring 36; that is to say, if thecompressive forces of the spring 36 are in the order of 1500 pounds, theweight of the aforementioned assembly must be something in excess ofthis amount. It was with respect to this requirement that the minordifference in the relative sizes of the shank Il were mentioned. Inpresent drilling apparatus, the shank Il and the drill bit l2, together,usually weigh in the order of a ton. If a compression spring of 1500pounds is used, the hammer assembly would necessarily add an additionalweight to that of a conventional shank sufficient t provide a cockingforce for the spring 36.

In summation, the instant invention provides means for storing energy onthe lift stroke/of the drill which heretofore has been dissipated aswaste energy, or at least has not been utilized. Thus, the instantinvention is operable to provide an initial gravity blow equivalent tothe lweight of the apparatus dropped and to thereafter apply a powerstroke to the drill bit in addition to that of the gravity strokeapproximately in the order of its quantitative value. Also, the bit isgiven a rotative movement which adds an additional cutting force to thetool to thereby greatly increase overall drilling eiiiciencies.

While a particular embodimentl of the invention has been illustrated anddescribed, it is apparent that the same is subject to other changes andmodifications. Accordingly, the representations and descriptions hereinmade are to be considered as illustrative only and not in a limitingsense, and the invention is to be defined solely by the appended claims.

What is claimed is:

1. In combination, in a double blow drill construction, a casing, a bitattachment member reciprocably mounted in said casing, a hammer memberreciprocably mounted in said casing adapted to be moved into drillingimpact engagement with said bit attachment member, means mounted withinsaid casing for attachably receiving a drop cable, releasable powermeans within said casing and above said bit attachment member for movingsaid hammer member into drilling :impact engagement with said bitattachment member, means within said casing for releasably restrainingsaid power means, and means within said casing engageableV with saidrestraining means for releasing said restrainng means and therethroughsaid power means immediately following drilling impact of said bitattachment member.

2. A double blow cable drill construction as set forth in claim l andincluding means for restoring said power means Vto hammer member movingposition effective during the cable lift of said drill construction.

3. A double blowy cable drill construction as set forth in claim l inwhich said hammer member is movable relative to said means forattachably receiving a drop cable to insure against snapping of the dropcable upon drilling actuation of said power means.l

4. A double blow cable drill construction as set forth inV claim l inwhich said power means com'- prises a strong resilient member which isunder compression when restrained and which expands to exert a drillingforce on said hammer member when released. U

5. In combinationdouble blow cable drill construction comprisingasleeve, a bit mounting member disposed in said sleeve for limitedreciprocative movement relative thereto, a cable attachment memberdisposed in said sleeve for limited reciprocable movement relativethereto, said members being in axial alignment, a hammer member in said,sleeve concentric withr said cable attachment member and in axialalignment with said bit mounting member, said hammer member beingaxially movable both with said cable attachment member and relativethereto, said hammer member being axially movable into strikingengagement with said bit mounting member, power means for moving saidhammer member into striking engagement with said bit mounting member,releasable means normally maintaining said power means against hammermoving action, and means for releasing said releasable means immediatelyfollowing drop drilling impact of said bit mounting member so that saidpower means is effective to drive said hammer member against said bitmounting member with drilling effect.

6. In combination, double blow cable drill construction comprising asleeve, a bit mounting member disposed in said sleeve for limitedreciprocative movement relative thereto, a cable attachment memberdisposed in said sleeve for limited reciprocable movement relativethereto, said members being in axial alignment, a hammer member in saidsleeve concentric with said cable attachment member and in axialalignment with said bit mounting member, said hammer member beingaxially movable both with said cable attachment member and relativethereto, said hammer member being axially movable into strikingengagement with said bit mounting member, power means for moving saidhammer member into striking engagement with said bit mounting member,releasable means normally maintaining said power means against hammermoving action, means for releasing said releasable means immediatelyfollowing drop drilling impact of said bit mounting member so that saida power means is eifective to drive said hammer member against said bitmounting member with drilling effect, and means for restoring said powermeans to releasably maintained position during cable lifting of saiddrill construction.

7. A double blow cable drill construction like claim 5 in which saidpower means comprises a strong resilient member which is undercompression when restrained and which expands to exert a drilling forceon said hammer member.

8. In combination, drill construction comprising an outer sleeve, abitmounting member within said sleeve having limited reciprocal axialmovement relative thereto, a bell member Within said sleeve havinglimited reciprocative axial movement relative thereto and being spacedaxially from said bit mounting member, a hammer member axiallyreciprocatable within said bell member and extending therefrom towardssaid bit mounting member, a heavy spring within said hammer member,diametrically aligned apertures in said outer sleeve, diametricallyaligned axially extending slots in said bell member, a diametric axiallyelongated opening in said hammer member, a pin mounted in said aperturesand extending through said slots and opening, said bell member beingfreely reciprocable axially relative to said pin for the length of saidslots therein, said spring having one end against said Ipin and theother end against said hammer member biasing said hammer member towardssaid bit mounting member, dogs pivotally mounted in recesses in saidouter sleeve, each dog including one free end adapted to engage thehammer member to maintain it in spring compressing position when saiddog is `in one extreme position of movement, each free end including anangularly disposed surface engageable by theA lower edge of saidbell'member to free the dog from hammer member restraining position inthe lowermost position of said hammer member, each dog including anotherfree end adapted to be engaged by said bit'mounting member when in theother extreme position of movement to pivot said dog into hammer memberengaging position, and means for connecting said bell member to a cable.

' CARL C. KOELN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number n, Name Date 1,697,570 Mecom Jan. l, 19291,745,351 Bishop Feb. 4, 1930 1,810,391 Boynton June 16, 1931 2,252,912Armentrout Aug. 19, 1941 2,371,498 Boynton l Mar. 13, 1945 FOREIGNPATENTS Number Country Date 152,651 Germany June 20, 1904

